Dental matrix



NOV. 14, 1933. 1. F. NELSON 1,935,481

DENTAL MATRIX Filed July 21, 1932 if. F 625071,

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Patented Nov. 14, 1933 PAT-ENT ojPFlcr-: I'

DENTAL Marnix y .'fosephi FQNel's'on, lztfsons;- Kans'. l l Y Application July 2,1,"1932', Serial No.' 623,863'

1 u-olaims. rossa-'17) l'Ihernvent'ion relates to dentistry andhas particular reference to matrices usedv forV forming withithewallsof an interproximal cavity inthe tooth-a wallf to permit llin'g oflthe cavity conveniently'andtopr'event the iilling squeezingintoV thespace'betweenthe tooth operated'on and the adjacent tooth;- 1 l Heretofore it has been the practice to provide aY band: of steel or other suitable metal that is l-Of eitherclinc'hed around the tooth to be operated.

on or held in position by'means of a screw clamp on which is'mounted wedges to engagexbetween .the teethgv/hioh is uncomfortable'and in some instances painful tothe subject and which enl tails more time and difficulty in adjusting because" of thezfactthat the band is separatezfrom the retaining; clamp. i

'llliis'invention7 has for its object the provision of a matrix for interproximal cavities that may be used withaminimum.k discomfort to the subject-"andthat is'extremely low in cost and ver'y durable, r

A-further object of the invention is the provisionv of' a dental' matrix that is universal in its 251' application, being capablev of use in all positions in themouth; except4 the six anterior teeth above and below, Ydispensing Vwith the necessityl ofy al j collection ofi sizes, and thatv can be quickly and easily placed in `position and removed.

Thefinvention will be described in'detail hereinafter and will:v beiound illustrated in the accompanying drawing, in which Figure 1j is`a top plan view of the improved dental .matrix showing it' inzpositionbetween two. V355y molar teeth, Y i

' Figur-'e12-is' a sideview in elevation,

Figure 3'i's' asimilar view ofthe opposite side of the matrix showing the wedges in theiroutermost positions',gr

Figure 4 is a similar view showing the wedge members in their innermostror clamping positions, Y

Figure 5 is a sectional view ofa slightly enlarged scale on a plane indicated by the line 5--5 of Figure 2, n

Figure 6 is a sectional View on a plane indicated by theline 6-6 of Figure 2, Y Y Figure '7 is a sectional detail View on a plane mindicated by the line 7-7 of Figure',

Figure 8 is1 a view in elevation of one of the wedge members, and

Figure 9 is a view in elevation of the matrix band. ;l In the drawing similar reference characters are used to designate corresponding'parts in` all' the vieWs.-.` y v:

The improved dental matrix as shown' in the drawing. includes aY frame" .having an arcuate shaped horizontal bar 10 ywith itsintermediate 60,

portion oiise't inwardly as shown at 11, and Ver,-1

tically arranged andspaced tubular guides 12in whichv are slidably. mounted wedgemembers 13- having their inneradjacent ends reducedV and forming, forwardly projected prongs 1 4 having their upper edges inclined' downwardlyl and out'- wardly thereof as shown at 15. A'Ihebar 10 is,Y adapted to seat on the tooth Aadjacent to; the tooth that is'to beoperated on as shownin Figure l, and the upwardly offset portion 11 isprovided for convenience in placing Aand removing the same. In Figure 1VV the toothr AV is shown to be. provided with an interproximal cavity-V a and B ldesignates the-adjacent'tooth. The wedges 13 are provided- Withvlongitudinalslots 16y to receiveV studs or projections von the tubular guide members, designated 17, that provide means for limiting the 'sliding movement of the wedges 13, said; ,studs or projections may bel formed 'by indenting the material of theguide'members; as shown in the drawing-or any Aother provision of studs or projections may besubstituted therefor as may be apparent.` The'wedges are also'provided with slotsfllconnecting the outer forwardedge of the wedge member with the slots in each instance, thus providing a bifurcated wedge structure, and as the furcations formed by this structureare tensioned to normallyspring outwardly, the upper and lower edges of' the wedge members friction-` ally lengage Itheupper and lower walls of the guide members 12'and serve to hold the wedges frictionally in adjustedpositions against acciden-` taldisplacement.l The outer portion of eachv wedge 13 is alsoprovided with an opening 19 to receive a pointed instrument for convenience vin adjusting the position of the wedges veither in placing or removing the matrix;

Secured 'to or formed integral with each of the guide members 12 is an arm 20 that is arranged at an angle to the guide member in each instance, and having a tongue. 21 returned on said arm and spaced therefrom to receive the ends of a matrix band 22 therebetween, said band having its ends bent and returned to engage the outer edges of the arm 2O on each side of the frame as shown 105 at 23. By providing the arms 20 at angles to the guide members 12 it will be apparent that the mate the contour of the tooth.

The arm 2() with the returned tongue 21 forms a tensioned clip which holds the matrix band 22 securely and provides a means for removal and replacement of matrix bands and thereby enables the operator to use bands of different widths and to vreplace an old band with a new one.

In use it will be apparent that the device is inserted so that the concaved portion of the band 22 engages the side of the tooth to be filled, the wedge members 13 being withdrawn outwardly in the position shown in Figure 3. After the band and the device is in position wedge members 13 are moved inwardly toward one another approximating the position shown in Figure 4, and

the adjacent edges of the Wedge members 13 engage the band 22 to hold it in engagement with the side of a tooth, and the pointed extensions 14 serve not only to hold the band'in engagement with the side of the tooth, but also toprevent accidental displacement of the device while in position. The band When in position as shown in Figure 1 provides With the walls of the cavity in the tooth amatrix to receive the filling and prevents the iilling from squeezing out into the l soft gum tissues between the teeth and at the 2. Afdental matrix, comprising a frame havingtubular guide-ways, wedge members slidably mounted in said guide-ways, means limiting the movements of said wedges, a matrix band, and means on said frame to retain said band in position therein.

3.V A dental matrix, comprising Ya frame having tubular guide-ways, wedge members slidably mountedin said guide-ways, said Wedges being bifurcated and having the furcations under tension and in engagement with opposite walls ot said guide-ways providing a binding action therewith, a'matrix band, and means on said frame to retain said band in position therein.

4. A dental matrix, comprising a frame having tubular guide-Ways, wedges slidably mounted 'on said guide-ways and having slots therein, projections in said guide-Ways engaging in said slots to limit the movements ofthe wedges, a matrix band, and means on said frame to retain said band in position therein.

1,935,481' i f i 5. A dental matrix, comprising a frame, wedge members slidably mounted said frame, the frame including bifurcated supporting members, and a matrix band mounted in said supporting members and cooperating with said wedges. Y

6. A dental matrix, comprising a frame, wedge members slidably mounted in said frame, the frame including bifurcated supporting members arranged at an angle to said wedges, and a matrix band mounted in said supporting members and cooperating with said wedges.

'7. A dental matrix, comprising a frame, wedge members slidably mounted in said frame, the frame including arms extending at -an angle to said wedges, tongues on said arms rebent thereon and spaced therefrom to provide supports, and a -matrix band mounted in said supports and cooperating with said Wedges.n

8. A dental matrix, comprising a frame, wedge members slidably mounted in said frame, tubular guide-ways mounting'said wedge membersfthe wedge members bifurcated and havingiurcations under tension to frictionally engage .opposite walls of said guide-ways, projections in saidY tubular members engaging between said'furcations 10o to limit the movement ofV said wedge members, said frame including arms arranged atan angle to said-guide-Ways, tongues on said arms rebent thereon and spaced therefrom, and a matrixzband mounted between the arms and tongues and co- 195 operating with said wedges. Y A.

9. A dental matrix, comprisinga frame provided with a horizontal bar, and including guideE ways, wedge members slidably mountedin said guide-Ways, supporting members angularly ar-11`10 ranged relatively to-.said guide-ways, 'and a removable matrix band mounted in said supportingy members and engageable by said Wedge members in one of their positions. 1

10. A dentalmatrix, comprising a frame pro-:1115 vided with a horizontal bar having anrupwardlyv oiset portion intermediate of its ends, guide-ways mounted .on said bar, wedge membersY slidably mounted in said guide-ways, supporting members angular-1y arranged relatively to said guide-ways, 120 and a removable matrix bandmounted in. said' supporting members and engageable by.' said wedge members inone of their positions. L l

ll. A dental matrix; comprising aframe'prov videdV with an .arcuate horizontal bar having an upwardly oiset portion intermediate of its ends; guide-ways mounted on said bar, Wedge members slidably mounted in said guide-Ways, supporting members angularly arranged relatively to said guide-ways, and a removable matrix band mount- 13@v ed in said supporting members rand engageable by said Wedge members inone of their positions.

JOSEPHV F. NELSON. 

